I really like this technical drawing stuff... personally I dont think its boring at all, and if it still just a wip, I cant wait to see the finished product.
Sombody mentioned that the trains might benefit from being scaled down... personally I agree with this, then maybe you can put more time into shading and lighting... also you might find it easier to detail the train if it were smaller. That being said, I dont mind the scale you chose, just seems like it would take a long time to make a finished product.
One critque that I noticed while admiring your work. The wheels look like there resting on the rails with no backing to keep the train in place, there should be part of the wheel going past the inside of the track to keep the train from falling off... If you going for realism, which I think you are, you might want to fix this before you get to far. In fact changing this now might actually be a bit of work as I notice some of the wheel placements are kinda close, and adding to the current wheels diameter might cause some overlapping.
I remember this piece a while back and thought about how cool it would be to animate. good job.